Computer-Assisted Instruction ; Education, Medical ; Internet ; Language ; Medicine, Chinese Traditional

Animals ; Electrocardiography ; Heart ; physiology ; physiopathology ; Heart Rate ; physiology ; Humans ; Noise ; adverse effects ; Rats

Objective To investigate the effects of recombinant human growth hormone (rhGH) on tumor growth and tumor angiogenesis factor relevant to Janus kinase 2-signal transducer and activator of transcription 3 of human gastric carcinoma xenografts in nude mice with different expressions of growth hormone receptor (GHR).Methods Immunocytochemical method was used to pick out one GHR-positive and one GHR-negative cell line. The cells were subcutaneously injected into 26 nude mice separately, then the patterns of xenografts in nude mice with different expressions of GHR were established. The nude mice bearing two different kinds of human gastric caicinoma were equally randomized into control group, low-dose rhGH group, and high-dose rhGH group,and were treated with drugs for 14 days. Changes of tumor volumes and body weight of nude mice were record. The protein and mRN A expressions of tumor angiogenesis factor in tumor tissue were detected by RT-PCR and Western blot, respectively. Results GHR was highly expressed in SGC-7901 celk but negative in MKN-45 cells. For nude mice bearing GHR+ SGC-7901 xenografts, the tumor volumes were significantly larger in low-dose rhGH group [(1. 141 ±0. 234) cm3] and high-dose rhGH group [(2. 106 ±0. 260) cm3] than in control group [(0.612±0. 156) cm3] (P = 0. 034, P = 0. 001), and the high-dose rhGH group revealed greater effect (P =0. 043 ). Body weight was not significantly different among three groups. Compared with the control group, the mRNA expressions of tumor angiogenesis factor were significantly increased in low-does rhGH group, and the P values of GHR, Janus kinase 2, signal transducer and activator of transcription 3, vascular endothelial growth factor (VEGF), hypoxia-inducible factor-1α (HIF-1α), fibroblast growth factor, and matrix metalloproteinases-2 (MMP-2) was 0.001, 0.011, 0.042, 0.045, 0.040, 0.002, and 0.003, respectively; however, the high-does rhGH group did not show the greater effects. The protein expressions were significantly increased in low-does rhGH group, and the P value of phosphorylation-signal transducer and activator of transcription 3, signal transducer and activator of transcription 3, VEGF, HIF-1α, and MMP-2 was 0. 015, 0.003, 0.010, 0.008,and 0. 005, respectively; furthermore, the high-does group revealed the further greater effects, and the P value of VEGF, HIF-1α, and MMP-2 was 0.012, 0.025, and 0.046, respectively. On the contrary, for nude mice bearing GHR- MKN-45 xenografts, the body weights of low-dose rhGH group [(24.94 ±0. 517) g] and high-dose rhGH group [(26.97 ±0.686) g] were significantly higher than that of control group [(22.78 ±0.418) g] (P =0. 040, P = 0.012 ) , while tumor growth as well as the expressions of mRNA and protein of tumor angiogenesis factor in tumor tissue were not significantly different Conclusions rhGH can promote tumor growth and up-regulate the expression of tumor angiogenesis factor in the GHR-highly-expressed SGC-7901 xenograft tumor model; However,such effects do not exist in GHR-negatively-expressed MKN-45 xenograft tumor model. The existence of GHR may be a key target by which rhGH influences the tumor growth and the expressions of tumor angiogenesis factor, which is probably achieved through Janus kinase 2-signal transducer and activator of transcription 3 activation.

Objective To evaluate the safety and accuracy of CT-guided cutting needle biopsy for the hepatic lesions near diaphragmatic dome.Methods A total of 25 cases with hepatic lesions near the diaphragmatic dome were undertaken CT-guided cutting needle biopsy using 16 gauge or 18 gauge core biopsy needles.Results Histological examination showed malignancy in 17 cases and benign in 8 with 2 false negative results(8%),and there were no false positive results.The specificities of malignant and benign lesions were 100% and 75%,respectively.Overall accuracy was 92%.Pneumothorax,needle tract hemorrhage,and subcapsular hepatic hemorrhage occurred in 2(8%),1(4%)and 1(4%),respectively.Conclusion CT-guided cutting needle biopsy for the hepatic lesions near diaphragmatic dome is a reliable and relatively safe diagnostic method.(J Intervent Radiol,2007,16:838-840)

One alkaline protease from Actinomucor elegans AS3.2778 was purified protein. The enzyme was purified using ammonium sulfate precipitation, ion exchange chromatography, hydrophobic chromatography and size exclusion chromatography method, and its properties were also investigated. The molecular weight of this enzyme is 32 kDa with SDS-PAGE method, optimum temperature is 60℃, optimum pH is 8.5 to 10.5, it is stable in the pH range of 6.0 to 9.0 at < 40℃ temperature, and being completely inhibited by the serine protease inhibitor, PMSF, indicated that it belongs to the serine protease family. Specificity test indicated this protease has extensive selectivity to peptide bones, especially to peptide bones composed of Leucine residue.

Animals ; Disease Models, Animal ; Sleep Deprivation ; physiopathology ; psychology

ObjectiveTo investigate the mechanisms of neonatal transplantation tolerance,especially the role of immature immune system and chimerism in tolerance.MethodsF1 ( or GFP-F1 ) mice were bred by crossing male C57BL/6 (or GPF transgenic C57BL/6) and female BALB/c mice. Within 24 h,newborn C57BL/6 mice were inoculated with different doses of splenocytes from F1 or GFP-F1 mice,irradiated spleen cells were used as control.Six weeks later,the mice were subjected to F1 skin grafting,and mixed-lymphocyte reaction was performed to determine their tolerance.Flow analysis was used to detect chimerism.ResultsLiving F1 spleen cells could induce chimerism and neonatal transplantation tolerance,but irradiated cells not.The chimerism in long-term tolerant mice is higher than that in chronic rejected mice,with 6.48％ ±4.02％ vs 1.57％ ±0.89％,the difference is significant in statistical analysis.The degree of neonatal transplantation tolerance is determined by the dosage of donor cells,the mice induced with 3 × 107 F1 spleen cells have 80％ long-term tolerance,but the dose of0.7×107 F1 spleen cells could only prolong allografts survival.ConclusionNeonatal transplantation tolerance is dependent on chimerism,the chimerism of donor cells leads to clonal deletion of alloreactive T cells.

0.05). ConclusionsTwo methods of fibero tomy do not effect on the periodontal tissues. The PSP is more excellent than t he MSF in preventing the corrected teeth from relapsing and keeping the aest hetic feeling of the gingival shape.

Traditional recombination technology of bacteria chromosome and its limitation were introduced. The definition of Red recombination technology is put forward: a method of homologous recombination between foreign linear DNA and the target gene in chromosomes mediated by ? phage Red system. The linear DNA referred here is general PCR product or oligonucleotide, which has a 36~50bp homologous sequence with the target gene in chromosome at both flanking. Red recombination technology leaves out the in vitro DNA restriction enzyme digestion and link process, which makes the knockout and alternation of target gene in bacteria chromosome relatively easier, and becomes an effective method to exploring genes and constructing new strains gradually. The gene inactivation and alternation method aiming at bacteria chromosome applied to Red recombination system was summarized by the structure element, action mechanism, and strategy of recombination, advantage and developing prospect. The Red system includes three genes: bet (aka?), exo and gam (aka ?). Exo is a 5′→3′ exonuclease, which degrades the 5′ ends of linear DNA molecules. Bet is a single-stranded DNA binding protein that binds to the single stranded 3′ ends generated by Exo and promotes annealing to complementary DNA. Gam binds to the host RecBCD complex and inhibits its exonuclease activity. Red recombination system may be constructed in such plasmids as pKD20 and pKD46 or in chromosome of bacteria. Most bacteria are not readily transformable with linear DNA because of the presence of intracellular exonucleases that degrade linear DNA. But when bacteria cells are transformed with pKD20 or pKD46 plasmid, or integrated with a detective ? prophage, Red recombination enzymes may be expressed in host cells, which make linear DNA with 36~50bp extensions that are homologous to both flanking of target genes transform E.coli readily and knock-out or alternate target gene. The Red recombination method is not only useful in chromosomal gene inactivation in E.coli, but also in other bacteria or virus, such as Salmonella, Shigella flexneri and virus HaSNPV. With the proceeding research, Red system will be applied for more and more purposes, and contribute a lot for gene improvement and gene function investigation in the coming Postgenome Era.

Objective To compare proximal femoral nail(PFN)introduction by percutaneous K-wire through a small incision with conventional PFN introduction protocol in the treatment of intertrochanteric fractures. Methods From January 2004 to March 2005,51 patients with intertrochanteric fractures were randomly dis- tributed into a minimally invasive treatment group(group MI)and a conventional treatment group(group C).All the fractures were closely reduced.In group MI a K-wire was percutaneously inserted through the tip of the greater troehanter into the center of medullary canal of the pruximal femur before the PFN was inserted under the guidance of K-wire through a small incision made along the K-wire while in group C the PFN was introduced according to the conventional procedure.The operation time,intra-operative blood loss,length of incision,X-ray exposure,duration of in-patient stay and time of bone union in both groups were recorded and compared.Results The mean oper- ation time,mean intraoperative blood loss and mean length of incisions in group MI were 77.20 min,104.20 mL and 5.12 cm respectively and significantly lower than those in group C(P＜0.01).The X-ray exposure and the reduction time in group MI lasted longer than in group C(P＜0.01).The mean time of bone union and in-patient stay in both groups were nearly equal(P＞0.05).At the latest tollow-up,all the fractures united in both groups without nonuuion or delayed union.Conclusion Compared with the conventional protocol,introduction of PFN by a pereutaneuus K-wire inserted into the central medullary canal of the proximal femur is much more minimally in- vasive and effective.